Phase to Phase: A phase to B phase would be the phase to neutral times square root of 3.

I see this as a new phasor AB being ahead of the A phase.
But I am confused in this drawing why -EB0 is drawn as a phasor the way that it is.
Why did the author redraw the phase B to neutral this way? It's already drawn in at 120° shift. Why then draw a new one and add a negative in front of the voltage symbol?